The invention relates to reinforcement fibers and/or process fibers based on plant fibers, methods for their production, and their use.
It is known that asbestos fibers are frequently mixed to molded parts. Recently, major adverse health concerns have been expressed regarding the use of asbestos fibers. In spite of this disadvantage, these fibers continue to be used to a large extent because they provide significant advantages in many fields of application and genuine alternatives are not presently on the market at this time.
The same applies for glass fibers. Artificial fibers also are considered to have major adverse health concerns because they release toxic vapors at increased temperatures during breakdown reactions.
Attempts have also been made to find a substitute material for asbestos based on plant fibers. West German Patent DE-OS 30 08 204 describes a method for the production of reinforcing fibers in which the capillaries of the plant fibers are initially opened after an intermediate drying process, using a solution of sodium silicate containing formaldehyde. The plant fibers are subsequently impregnated with a slurry of lime and water. These treatment steps can also be carried out in reverse sequence. This method, however, has also not led to the desired success.